Method and apparatus for generating side information bitstream of multi-object audio signal

ABSTRACT

Provided is a method and apparatus for generating a side information bitstream of a multi-object audio signal. The apparatus for generating a side information bitstream of a multi-object audio signal includes a spatial cue information input unit configured to receive spatial cue information generated in an encoder of the multi-object audio signal, a preset information input unit configured to receive preset information for the multi-object audio signal, and a side information bitstream generator configured to generate the side information bitstream based on the spatial cue information and the preset information. The side information bitstream includes a header region and a frame region, and the preset information is included in the frame region.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/933,019, filed Sep. 16, 2010, which is a 35 U.S.C. §371 nationalstage filing of PCT Application No. PCT/KR2009/001615 filed on Mar. 30,2009, which claims priority to, and the benefit of, Korean PatentApplication No. 10-2008-0029562 filed on Mar. 31, 2008, Korean PatentApplication No. 10-2008-0034161 filed on Apr. 14, 2008 and Korean PatentApplication No. 10-2008-0024374 filed on Mar. 23, 2009. The contents ofthe aforementioned applications are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a method and apparatus for generating aside information bitstream of a multi-object audio signal.

This work was supported by the IT R&D program of MIC/IITA[2008-F-011-01, Developing Next Generation DTV Core Technology(Standardization Linkage), Developing Autostereoscopic Personal 3-DBroadcasting Technology (Continued)].

BACKGROUND ART

A conventional technology for encoding and decoding an audio signal doesnot combine different types of audio objects such as a mono-channelaudio object, a stereo channel audio object, and a multi-channel audioobject. That is, the conventional audio signal encoding and decodingtechnology did not allow a user to consume one type of audio contents indiverse ways. Accordingly, a user has passively consumed the audiocontents.

A spatial audio coding (SAC) technology encodes a multi-channel audiosignal into a down-mixed mono-channel signal or a down-mixed stereochannel signal with spatial cue information and transmits a high qualitymulti-channel signal even at a low bit rate. The SAC technology alsoanalyzes an audio signal by each sub-band and restores an originalmulti-channel audio signal from the down-mixed mono-channel signal orthe down-mixed stereo channel signal based on spatial cue informationcorresponding to each sub-band. The spatial cue information includesinformation for restoring an original signal in a decoding process anddecides the quality of an audio signal to be reproduced in a SACdecoding apparatus. MPEG has been progressed the standardization of theSAC technology as MPEG Surround (MPS) and has used channel leveldifference as a main spatial cue.

Since the SAC technology allows encoding and decoding a multi-channelaudio signal formed of only one audio object type, it is impossible toencode or decode an audio signal having various types of audio objectssuch as a mono-channel audio object, a stereo channel audio object, or amulti-channel audio object such as 5.1 channels using the SACtechnology.

A binaural cue coding (BCC) technology according to the prior art wasintroduced to encode or decode a multi-object audio signal formed ofmono-channel audio objects. However, a multi-object audio signal formedof multiple channel audio objects could not be encoded or decoded usingthe binaural cue coding BCC technology.

As described above, the conventional audio encoding and decodingtechnologies cannot be used to encode or decode a multi-object audiosignal having multi-channel audio objects although a single object audiosignal formed of multi-channel audio objects or a multi-object audiosignal formed of mono-channel audio objects. Therefore, a plurality ofdifferent channel audio objects cannot be combined based on theconventional audio encoding and decoding technologies. That is, a usercould not consume one type of audio contents in various ways. Theconventional audio encoding and decoding technology allows a user onlyto passively consume audio contents.

DISCLOSURE

1. Technical Problem

An embodiment of the present invention is directed to providing a methodand apparatus for changing audio scene information set-up (ex. Preset)according to the intention of a sound engineer or an editor whilereproducing a multi-object audio signal by including preset informationin a frame region of the side information bitstream that is generatedwhen the multi-object audio signal is encoded.

Other objects and advantages of the present invention can be understoodby the following description, and become apparent with reference to theembodiments of the present invention. Also, it is obvious to thoseskilled in the art of the present invention that the objects andadvantages of the present invention can be realized by the means asclaimed and combinations thereof.

2. Technical Solution

In accordance with an aspect of the present invention, there is providedan apparatus for generating a side information bitstream of amulti-object audio signal, including a spatial cue information inputunit configured to receive spatial cue information generated in anencoder of the multi-object audio signal, a preset information inputunit configured to receive preset information for the multi-object audiosignal, and a side information bitstream generator configured togenerate the side information bitstream based on the spatial cueinformation and the preset information, wherein the side informationbitstream includes a header region and a frame region, and the presetinformation is included in the frame region.

In accordance with another aspect of the present invention, there isprovided an apparatus for analyzing a side information bitstream of amulti-object audio signal, including a side information bitstream inputunit configured to receive the side information bitstream, a spatial cueinformation extractor configured to extract spatial cue informationbased on the side information bitstream, and a preset informationextractor configured to extract preset information based on the sideinformation bitstream, wherein the side information bitstream includes aheader region and a frame region, and the preset information is includedin the frame region.

In accordance with another aspect of the present invention, there isprovided an apparatus for encoding a multi-object audio signal,including an encoder configured to down-mix an audio signal formed of aplurality of objects and generate spatial cue information for an audiosignal formed of the plurality of objects, and a side bitstreamgenerator configured to generate a side information bitstream based onpreset information for the spatial cue information and the audio signal,wherein the side information bitstream includes a header region and aframe region, and the preset information is included in the frameregion.

In accordance with another aspect of the present invention, there isprovided an apparatus for decoding a multi-object audio signal,including a side information bitstream analyzer configured to receive aside information bitstream and extract spatial cue information andpreset information included in the side information bitstream, a decoderconfigured to restore an audio signal formed of a plurality of audioobjects based on the spatial cue information from an input down-mixedaudio signal, and a renderer configured to render an audio signal formedof the plurality of objects into an audio signal formed of a pluralityof channels based on the preset information, wherein the sideinformation bitstream includes a header region and a frame region, andthe preset information is included in the frame region.

In accordance with another aspect of the present invention, there isprovided a method for generating a side information bitstream of amulti-object audio signal, including receiving spatial cue informationgenerated in an encoder of the multi-object audio signal, receivingpreset information of the multi-object audio signal, and generating theside information bitstream based on the spatial cue information and thepreset information, wherein the side information bitstream includes aheader region and a frame region, and the preset information is includedin the frame region.

In accordance with another aspect of the present invention, there isprovided a method for analyzing a side information bitstream of amulti-object audio signal, including receiving the side informationbitstream, extracting spatial cue information based on the sideinformation bitstream, and extracting preset information based on theside information bitstream, wherein the side information bitstreamincludes a header region and a frame region, and the preset informationis included in the frame region.

In accordance with another aspect of the present invention, there isprovided a method for encoding a multi-object audio signal, including:down-mixing an audio signal formed of a plurality of objects andgenerating spatial cue information for an audio signal formed of aplurality of objects, and generating a side information bitstream basedon preset information for the spatial cue information and the audiosignal, wherein the side information bitstream includes a header regionand a frame region, and the preset information is included in the frameregion.

In accordance with another aspect of the present invention, there isprovided a method for decoding a multi-object audio signal, including:receiving a side information bitstream and extracting spatial cueinformation and preset information included in the side bitstream;restoring an audio signal formed of a plurality of objects based on thespatial cue information from an input down-mixed audio signal; andrendering the audio signal formed of the plurality of objects to anaudio signal formed of a plurality of channels based on the presetinformation, wherein the side information bitstream includes a headerregion and a frame region, and the preset information is included in theframe region.

3. Advantageous Effects

A method and apparatus for generating a side information bitstream of amulti-object audio signal according to an embodiment of the presentinvention advantageously enables changing audio scene information set upaccording to the intention of an editor or a sound engineer whilereproducing a multi-object audio signal by including preset informationin a frame region of a side information bitstream generated when amulti-object audio signal is encoded.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram describing encoding, decoding, and rendering amulti-object audio signal in accordance with an embodiment of thepresent invention.

FIG. 2 illustrates a structure of a side information bitstream generatedusing a multi-object audio signal.

FIG. 3 illustrates a structure of a side information bitstream inaccordance with an embodiment of the present invention.

FIG. 4 illustrates a structure of a side information bitstream inaccordance with another embodiment of the present invention.

FIG. 5 illustrates a structure of a side information bitstream inaccordance with still another embodiment of the present invention.

BEST MODE FOR THE INVENTION

The advantages, features and aspects of the invention will becomeapparent from the following description of the embodiments withreference to the accompanying drawings, which is set forth hereinafter.When it is considered detailed description on a prior art may obscure apoint of the present invention, the description will not be providedherein.

The present invention relates a technology for compressing anddecompressing a multi-channel/multi-object audio signal. Multi-objectaudio encoding is a technology for compressing different audio objectstogether and transmitting the compressed audio objects. The multi-objectaudio encoding technology was developed based on a spatial audio coding(SAC) technology.

In a process of decoding a multi-object audio signal, an input audiosignal formed of multi-objects is down-mixed and transmitted to adecoding apparatus. Here, a side information bitstream is transmittedwith the down-mixed signal. The side information bitstream includesinformation necessary to reproduce a multi-object audio signal. Theinformation for reproducing a multi-object audio signal includes presetaudio scene information (Preset-AS I). Audiences of a multi-object audiosignal can enjoy various audio scenes using the preset information thatis set up by and provided from an editor or a sound engineer.

The side information bitstream is divided into a header region and aframe region. The preset information is only included in the headerregion. Accordingly, an audience is provided with only default presetinformation stored in the header region. After providing the defaultpreset information, it is impossible to update the preset information.

In order to overcome the problem, an embodiment of the present inventionprovides a technology for providing realistic audio scenes to audiencesby updating the preset information while reproducing a multi-objectaudio signal. In order to update the preset information, a method andapparatus for generating a side information bitstream according to thepresent invention includes the preset information in a frame region ofthe sub information bitstream. That is, a method and apparatus forgenerating a side information bitstream according to the presentinvention enables an audience to receive not only default presetinformation included in a header region but also optional presetinformation included in each frame by including the preset informationin the frame region and transmitting the preset information with theframe region.

For example, a chorus sound source is located at the front of a stagewith a main vocal sound source when a corresponding audio signal isinitially reproduced. Updated preset information may relocate the chorussound source to the rear of the stage at a predetermined time duringreproducing the audio signal. As another example, it is possible to movea location of a chorus sound source from the front of a stage or therear of the stage according to time during reproducing the audio signal.The method and apparatus for generating a side information bitstreamaccording to the present invention can improve a sound field of an audiosignal or form a dynamic sound scene.

Hereinafter, a method and apparatus for generating a side informationbitstream according to the present invention will be described withreference to the accompanying drawings. Like numeral references denotelike elements throughout the accompanying drawings.

FIG. 1 is a diagram for describing encoding, decoding, and rendering amulti-object audio signal in accordance with an embodiment of thepresent invention.

Referring to FIG. 1, a multi-object audio signal is encoded, decoded,and rendered through a SAOC encoder 102, a bitstream formatter 104, aSAOC decoder 106, a bitstream analyzer 108, a rendering matrix generator110, and a renderer 112 according to the present embodiment.

In multi-object spatial audio object coding (SAOC), a signal inputted asan audio object is encoded. Each of audio objects is restored by adecoder. The restored objects are not independently reproduced. Therestored objects are rendered based on information about audio objectsfor forming a specific audio scene and outputted as a multi-object audiosignal. Therefore, it is necessary to have an apparatus for renderinginformation about input audio objects in order to obtain a predeterminedaudio scene based on a multi-object audio signal.

The SAOC encoder 102 is a spatial cue based encoder and encodes an inputaudio signal as an audio object. Here, the audio object inputted to theSAOC encoder 102 may be a mono-channel audio signal or a stereo channelaudio signal. The SAOC encoder 102 outputs a down-mixed signal byencoding more than one audio object. The outputted down-mixed signal maybe a mono signal or a stereo signal. The SAOC encoder 102 extractsspatial cue parameters related to multi-object necessary to decode thedown-mixed signal. The SAOC encoder 102 may analyze an input audioobject signal based on a Heterogeneous Layout SAOC scheme or a Fallerscheme.

The extracted spatial cue parameter includes spatial cue information.The spatial cue is analyzed and extracted by a unit of a frequencydomain sub-band. The spatial cue is information used for encoding anddecoding an audio signal. The spatial cue is extracted from a frequencydomain and includes information about amplitude different, delaydifference, and correlation between two signals. For example, thespatial cue includes channel level difference (CLD), inter-channel leveldifference (ICLD), inter channel time difference (ICTD), inter channelcorrelation (ICC), and virtual source location information. However, thepresent invention is not limited thereto.

The spatial cue parameter includes information for restoring andcontrolling spatial cue and an audio signal. Particularly, headerinformation included in a spatial cue parameter includes information forrestoring and reproducing a multi-object audio signal formed of variouschannel type audio objects and defines channel information about anaudio object and an ID of a corresponding audio object, therebyproviding decoding information about mono-channel audio objects, stereochannel audio objects, and multi-channel audio objects. For example, theheader information may include information of Identification (ID) or anobject that enables identifying whether a coded audio object is amono-channel audio signal or a stereo channel audio signal.

The bitstream formatter 104 generates a side information bitstream (SAOCbitstream) based on preset information (Preset-ASI) from an externaldevice and the spatial cue parameters transferred from the SAOC encoder102.

The SAOC decoder 106 restores the down-mixed signal from the SAOCencoder 102 as a multi-object audio signal using the spatial cueparameter outputted from the bitstream analyzer 108. The SAOC decoder106 may be replaced with a MPEG surround decoder and a BCC decoder.

The bitstream analyzer 108 extracts spatial cue parameters and presetinformation by analyzing the side information bitstream outputted fromthe bitstream formatter 104. The extracted spatial cue parameters aretransferred to the SAOC decoder 106, and the preset information istransferred to a rendering matrix generator 110.

The rendering matrix generator 110 generates a rendering matrix usingthe preset information outputted from the bitstream analyzer 108 anduser control inputted from an external device. If the preset informationis not transmitted from the bitstream analyzer 108, the presetinformation is set up as default.

The renderer 112 renders a multi-object audio signal outputted from theSAOC decoder 106 to a multi-channel audio signal using the renderedmatrix outputted from the rendering matrix generator 110.

Although encoding, decoding, and rendering the multi-object audio signalaccording to the present embodiment were described with reference toFIG. 1, the side information bitstream according to the presentinvention is not limited thereto. That is, the present invention may beidentically applied to any structures for rendering multi-object signalsbased on preset information included in audio object signal.

FIG. 2 is a diagram for describing a structure of a side informationbitstream generated using a multi-object audio signal.

As shown in FIG. 2, the side information bitstream includes a headerregion and a frame region. The header region includes headerinformation, channel information of an audio object, ID information of acorresponding audio object, the number of audio objects by a channel.The frame region includes information about a real audio signal, forexample, spatial cue information.

The preset information means audio object control information andspeaker layout information. In more detail, the preset informationincludes speaker layout information, audio object location information,and level information in order to properly produce an audio scene. Thepreset information may be directly expressed or expressed in a matrixformation.

When the preset information is directly expressed, the presetinformation may include information about a layout of a playback systemsuch as a mono system, a stereo system, and a multi-channel system, anaudio object ID, an audio object layout (mono or stereo), an audioobject location, azimuth such as 0 degree to 360 degree, elevation suchas −50 degree to 90 degree, and an audio object level such as −50 dB to50 dB.

When the preset information is expressed in a matrix formation, thepreset information may have a form of a P matrix as shown in Eq. 1. Thepreset information expressed in the matrix includes power gaininformation to be mapped to an output channel or phase information aselement vectors.

$\begin{matrix}{{P \odot W_{oj}^{b}} = {{\underset{\underset{{Matrix}\mspace{14mu} I}{}}{\begin{bmatrix}p_{1,1}^{b} & p_{1,2}^{b} & \ldots & p_{1,{N - 1}}^{b} \\p_{2,1}^{b} & p_{2,2}^{b} & \ldots & p_{2,{N - 1}}^{b} \\\vdots & \vdots & \ddots & \vdots \\p_{M,1}^{b} & p_{M,2}^{b} & \ldots & p_{M,{N - 1}}^{b}\end{bmatrix}} \odot \begin{bmatrix}w_{{oj}\; \_ 1}^{b} \\w_{{oj}\; \_ \; 2}^{b} \\\vdots \\w_{{{oj}\; \_ \; N} - 1}^{b}\end{bmatrix}} = \begin{bmatrix}w_{{ch}\; \_ 1}^{b,} \\w_{{ch}\mspace{11mu} \_ 2}^{b} \\\vdots \\w_{{ch}\; \_ \; M}^{b}\end{bmatrix}_{SAOC}}} & {{Eq}.\mspace{14mu} 1}\end{matrix}$

The preset information may define diverse audio scenes of the same audiocontent to be proper to different reproducing scenarios. For example, aplurality of preset information set up for stereo or multichannelplayback systems such as 5.1 channel and 7.1 channel playback systemscan be generated to be proper to the objective of a playback service orthe intention of a contents producer. A user may select one of audioscene information among more than one audio scene information (ASI)included in the preset information. The selected audio scene informationis used to render a multi-object audio signal of corresponding audiocontents.

The side information bitstream includes preset information for renderinga multi-object audio signal. Such preset information was not included ina frame region according to the prior art. The preset information wasconventionally included in a header region only. Therefore, a user or anaudience was limitedly enabled to enjoy a multi-object audio signal onlyusing default preset information included in the header region.

FIG. 3 illustrates a structure of a side information bitstream inaccordance with an embodiment of the present invention.

Referring back to FIG. 2, the default preset information is included inthe header region only in the prior art. Therefore, it is impossible toprovide diverse preset information set up properly to an environmentvarying during reproducing an audio signal or set up properly themultiple intentions of a contents producer, an editor, or a soundengineer. In order to overcome such a shortcoming, the side informationbitstream according to the present embodiment includes presetinformation not only in a header region but also in a frame region.Therefore, the side information bitstream according to the presentembodiment enables providing preset information different from thedefault preset information included in a header region at apredetermined time point (or frame) while reproducing a multi-objectimage.

Referring to FIG. 3, a side information bitstream according to thepresent embodiment includes a header region and a frame region. Theheader region includes header information and default presetinformation. Since the header information was already described indetail, detail description thereof is omitted. The default presetinformation may be provided to a user at an initial stage of reproducinga multi-object audio signal.

The frame region includes more than one frame. As shown in FIG. 3, theframe region includes a first frame, a second frame, . . . , and ann^(th) frame. Each of the frames may include a plurality of information.FIG. 3 shows the frame region including spatial cue information andpreset information for convenience. As shown in FIG. 3, a first framemay include not only first spatial cue information but also first presetinformation. Similarly, the second frame includes second spatial cueinformation with second preset information.

By allocating a space in each frame to include preset information, it ispossible to provide preset information of a corresponding frame whilereproducing a multi-object audio signal. For example, the bitstreamanalyzer 108 of FIG. 1 sequentially analyzes a side informationbitstream from the bitstream formatter 104. The bitstream analyzer 108extracts default preset information by analyzing the header region andcontinuously extracts preset information included in a frame region byanalyzing the frame region. The bitstream analyzer 108 transmits theextracted preset information to the rendering matrix generator 110.Therefore, the bitstream analyzer 108 according to the presentembodiment can extract new preset information whenever the bitstreamanalyzer 108 analyzes each frame region and uses the extracted newpreset information to render a multi-object audio signal correspondingto a corresponding frame.

The preset information can be used in various ways by providing thepreset information by each frame. For example, if a frame including newpreset information is received while rendering each frame based on thedefault preset information of the header region at an initial stage ofreproducing a corresponding audio signal, the new preset information maybe applied only to render the corresponding frame or the new presetinformation may be applied for rendering remaining frames.

If another frame including different preset information is receivedafter applying the new preset information, the preset information of thenewly received frame will be applied to a corresponding frame. As amethod of using the default preset information included in the headerregion, it is possible to provide various preset information to a userby providing all of the default preset information of the header regionand the new preset information included in corresponding frames.

FIG. 4 is a diagram illustrating a structure of a side informationbitstream in accordance with another embodiment of the presentinvention.

Referring to FIG. 4, the side information bitstream includes a headerregion and a frame region. The header region includes header informationand default preset information. The frame region includes more than oneframe such as a first frame, a second frame, . . . , and a n^(th) frame.

In FIG. 4, the first frame includes a plurality of preset informationsuch as first preset information and second preset information.According to the side information bitstream according to the presentembodiment, a user receives more various preset information at a periodcorresponding to the first frame than any other period by including aplurality of preset information in one frame as shown in FIG. 4.

Although not shown in FIG. 4, the second frame may also have a pluralityof preset information like the first frame. Or, the second frame may notinclude any preset information.

Although it is not shown in FIG. 4, it is possible to include presetinformation into each frame in regular pattern. For example, the firstframe includes three preset information, the second frame includes nopreset information, the third frame includes three frames again, and thefourth frame includes no preset information.

In addition, it is possible to include preset information only into aparticular frame region as shown in FIG. 4. Furthermore, more than oneframe may be included in the frame region based on various applicablepatterns.

By setting various regions to include preset information by each frameas described above, it is possible to provide various audio sceneinformation about a multi-object audio signal corresponding to eachframe.

FIG. 5 is a diagram illustrating a structure of a side informationbitstream in accordance with another embodiment of the presentinvention.

Referring to FIG. 5, the side information bitstream (SAOC bitstream)includes a preset information region. (Preset-ASI region). The presetinformation region includes a plurality of preset information such asPreset-ASI (default), Preset-ASI (1) to (N). One preset informationincludes audio object control information and speaker layoutinformation. As described above, the preset information may be directlyexpressed or expressed in a matrix formation. In case of directlyexpressing, the preset information includes an object ID, an objecttype, a location, a speaker layout, and sound level information as manyas the number of objects. As shown in FIG. 5, the preset information maybe expressed in a matrix having such elements as element vectors.

The above described method according to the present invention can beembodied as a program and stored on a computer readable recordingmedium. The computer readable recording medium is any data storagedevice that can store data which can be thereafter read by the computersystem. The computer readable recording medium includes a read-onlymemory (ROM), a random-access memory (RAM), a CD-ROM, a floppy disk, ahard disk and an optical magnetic disk.

The present application contains subject matter related to Korean PatentApplication No. 2008-0029562, filed in the Korean Intellectual PropertyOffice on Mar. 31, 2008, and Korean Patent Application No. 2008-0034161,filed in the Korean Intellectual Property Office on Apr. 14, 2008, theentire contents of which is incorporated herein by reference.

While the present invention has been described with respect to thespecific embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

What is claimed is:
 1. A apparatus for processing a multi-object audiosignal comprising: a processor configured to: receive a downmix signalrelated to a plurality of audio objects; generate a plurality of audioobjects from the downmix signal; and render the plurality of audioobjects into a least one of channels using a preset information relatedto audio object or a playback system, wherein the preset informationincludes at least one of (i) a layout of a playback system for a monosystem, a stereo system and multi-channel system, (ii) an audio objectID, (iii) object location, (iv) object level and (v) a azimuth degreeand an elevation degree of the object.
 2. The apparatus of claim 1,wherein the processor renders the plurality of audio objects usingpreset information expressed in matrix information configuring thelayout and the object ID.
 3. The apparatus of claim 1, wherein thepreset information is used to define audio scene for rendering theplurality of audio objects.
 4. The apparatus of claim 1, wherein theprocessor generates the plurality of audio objects from the downmixsignal using spatial information.
 5. The apparatus of claim 1, whereinthe preset information is extracted from a frame of bitstream.
 6. Theapparatus of claim 1, wherein the frame includes one or more presetinformation.
 7. A method for processing a multi-object audio signalperformed by a processor comprising: receiving a downmix signal relatedto a plurality of audio objects; generating a plurality of audio objectsfrom the downmix signal; and rendering the plurality of audio objectsinto a least one of channels using a preset information related to audioobject or a playback system, wherein the preset information includes atleast one of (i) a layout of a playback system for a mono system, astereo system and multi-channel system, (ii) an audio object ID, (iii)object location, (iv) object level and (v) a azimuth degree and anelevation degree of the object.
 8. The method of claim 7, wherein therendering comprising: rendering the plurality of audio objects usingpreset information expressed in matrix information configuring thelayout and the object ID.
 9. The method of claim 7, wherein the presetinformation is used to define audio scene for rendering the plurality ofaudio objects.
 10. The method of claim 7, wherein the generatingcomprising: generating the plurality of audio objects from the downmixsignal using spatial information.
 11. The method of claim 7, wherein thepreset information is extracted from a frame of bitstream.
 12. Themethod of claim 7, wherein the frame includes one or more presetinformation